Good, but expensive. - Sea to Summit Ultra-Sil Compression Sack

Very compact, great to bring up backpacking to use for a day hike so you don't need to bring your whole bag. Nice that its "water proof" but it can't be fully submerged, according to sea to summit. I believe it is the same material as the ultra-sil daypack, but has a rolled top rather than a zipper and compression straps, not sure if this warrants the extra cost.

Bottom line, compression strap is

This review was written in the old system and had content requirements that are different than reviews written today.